A document released to senior members of the Worker's Party of Korea listed a number of new restrictions on cellphone use in the reclusive communist country, the Japanese newspaper The Mainichi Shimbun reported Thursday.
The regulations were required, the document said, because mobile phone users were "spreading cultural ideology based on capitalism" and "threatening the safety of the country and the revolutionary leadership."
The increased use of cellphones in North Korea had become " a means for the United States to overthrow the government," the memorandum said.
Officials were ordered to block "polluted" messages and prevent the use of mobile phones to spread information.
Users must now register their personal information and mobile phone number when purchasing a cellphone.
The ministry of information also ordered mobile phone companies not to connect to foreign networks near the border and disable cellphones that play music and display images.
More than 2 million North Koreans have cellphones, twice the number 16 months ago.